Many surgical procedures require a surgeon to intraoperatively assess changes in the position or orientation of one or more portions of a patient's anatomy. However, even in open surgeries, there can be obstructions that prevent a surgeon from viewing relevant anatomy at a surgical site, e.g., blood, adjacent soft tissue, etc. Traditional surgical procedures use imaging techniques, such as CT-scans, x-rays, etc., to pre-operatively plan for a desired anatomical correction and then to post-operatively assess whether the desired anatomical correction has been achieved. Viewing the anatomical changes intraoperatively using such imaging techniques can be difficult, however, as it may require interruption of the surgery. Also, many imaging techniques only provide snapshots illustrating progressive changes in a qualitative manner, but do not provide data of changes as they occur in real-time. A further limitation of such imaging techniques is that they may only provide qualitative data, thus requiring a surgeon to make a subjective assessment of when a desired anatomical orientation has been achieved. Such imaging techniques also expose the patient and the operating room staff to potentially-harmful radiation.
During a traditional pedicle subtraction osteotomy, surgeons remove bone from a vertebra of a patient suffering from a spinal deformity to correct spinal curvature. To intraoperatively determine when the appropriate amount of bone has been removed, the surgeon must be able to accurately assess the amount of correction that has been achieved at a given time. Traditionally, to make this assessment, the surgeon must step back from the surgical procedure while an imaging device is brought in and positioned to view the curvature of the spine. However, this provides only a subjective measure of angular correction and involves an interruption in the surgical procedure, adding time and inconvenience. Often times, this results in sub-optimal patient outcomes and repeat surgeries due to over- or under-correction of the deformity.
Thus, there is a need for improved systems and methods for intraoperatively measuring anatomical position and/or orientation.